• Journal of Bio-Environment Control
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• v.11 no.3
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• pp.115-120
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• 2002

Growth and development of Limonium spp.‘Ocean Blue’plantlets were studied under three levels of photosynthetic photon flux (PPF),70,150 and 220 $\mu$mol. $m^{-2}$ . $s^{-1}$ , two levels of $CO_2$ concentration, 500 and 1000 $\mu$mol. $m^{-1}$ , and two levels of number of air exchanges per hour (NAEH),0.1 $h^{-1}$ and 2.8 $h^{-l}$. Explants were obtained from photomixotrophically-micropropagated plantlets. Four explants per vessel were cultured under cool-white fluorescent lamps for 16 h. $d^{-1}$ at 25$\pm$11$^{\circ}C$ and 70~80% relative humidity. In treatments of 2.8 $h^{-1}$ NAEH, a 10 mm round hole made on the vessel cap was sealed with a microporous filter and two $CO_2$ concentrations in the culture rooms were provided from a liquefied $CO_2$ tank. Fresh and dry weights, height, length of the longest root, number of loaves, and leaf area significantly increased with increasing PPF and especially, $CO_2$ concentration. Growth was enhanced by a 2.8 $h^{-1}$ NAEH. Overall, treatment with a 220 $\mu$mol. $m^{-2}$ . $s^{-1}$ PPF and a 1000 $\mu$mol. $m^{-1}$ $CO_2$ resulted in the most vigorous growth of Limonium spp. ‘Ocean Blue’ plantlets.s.

• Journal of Bio-Environment Control
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• v.6 no.3
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• pp.168-175
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• 1997

In greenhouse, data on evapotranspiration or water consumption is important for the rational water management, irrigation planning, thermal environment analysis, and watering automation. But little investigations have been attempted to make clear the characteristics of water consumption in greenhouse. In this paper, evapotransplrations of lettuce and cucumber by cropping systems were investigated. And the correlations among evapotranspiration, pan evaporation, solar radiation, mean air temperature, and minimum relative humidity were analyzed. Experimental cropping systems of lettuce were soil culture and NFT system. Those of cucumber were soil culture, perlite culture, and rockwool culture. Total water consumption of lettuce was 2.62$\ell$/plant in soil culture and 1.71$\ell$/plant in NFT system. That of cucumber was 45.22$\ell$/plant in soil culture, 27.45$\ell$/plant in rockwool culture and 29.06$\ell$/plant in perlite culture. Therefore total water consumption of soil culture showed higher than soilless culture.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.1
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• pp.615-621
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• 2018

To enhance the energy saving and comfort of indoors, this study performed a stimulation of sound fluctuation, color temperature, and aroma. The experiment with EEG, HRV, and Vibra images was conducted in an environmental test room with a temperature of $25[^{\circ}C]$, relative humidity of 50[RH%], air current speed of 0.002[m/s], and illuminance of 1000[lux]. The stimulation experiment set up different sensory stimulation conditions, such as before exposure, single-sensory stimulation of fluctuation a=1.106 jazz music, single-sensory stimulation of RED color lighting, single-sensory stimulation of scent aroma, and multi-sensory stimulation of fluctuation a=1.106 jazz music, RED color lighting, and scent aroma. After the multi-sensory stimulation of fluctuation a=1.106 jazz music, RED color lighting and scent aroma, the capacity for work and attention were increased, and the stress index and fatigue degree were decreased. In addition, multi-sensory stimulation of fluctuation a=1.106 jazz music, RED color lighting, and scent aroma were effective in maintaining a stable heart and health. In addition, the Vibra image appeared to decrease tension/anxiety and stress. The multi-sensory stimulation of fluctuation a=1.106 jazz music, RED color lighting, and scent aroma help increase the Neuro-energy more than that by no exposure and single-sensory stimulation.

• Journal of the Korean Wood Science and Technology
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• v.44 no.3
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• pp.440-448
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• 2016

As recent buildings become more air tight, the natural ventilation rate is significantly reduced and it leads to difficulty in removing accumulated moisture in buildings. Hot and humid weather in summer and the large amount of moisture caused by indoor activity are the major factors of moisture problem in Korea. The hygrothermal behavior of building environment has to be considered carefully to reduce condensation risk and mold growth potential, and comfortable indoor environment. In this study, we evaluated hygrothermal behavior of Standard Wood-frame Structure published in the Korea Rural Community Corporation Using WUFI simulation program. The results indicated that the total water contents of wood wall measured in 2014 was lower than wood wall in 2010. As a result of evaluation by separating the farming and fishing areas, Moisture problems in fishing area became larger. The walls had a significant impact on the relative humidity than the temperature each areas. Furthermore, excessive water content problem of the wood-based material was reduced in the wall that could be applied in the fishing villages by changing the outdoor finishing materials. And Mold growth risk on the interior materials could be removed through the different setting of the indoor temperature during summertime.

• Journal of Environmental Science International
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• v.24 no.7
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• pp.851-864
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• 2015

This study analyzed the climate regime shift using statistical change-point analysis on the time-series tropical cyclone (TC) frequency that affected Japan in July to September. The result showed that there was a significant change in 1995 and since then, it showed a trend of rapidly decreasing frequency. To determine the reason for this, differences between 1995 to 2012 (9512) period and 1978 to 1994 (7894) period were analayzed. First, regarding TC genesis, TCs during the 9512 period showed a characteristic of genesis from the southeast quadrant of the tropical and subtropical western North Pacific and TCs during the 7894 period showed their genesis from the northwest quadrant. Regarding a TC track, TCs in the 7894 period had a strong trend of moving from the far east sea of the Philippines via the East China Sea to the mid-latitude region in East Asia while TCs in the 9512 period showed a trend of moving from the Philippines toward the southern part of China westward. Thus, TC intensity in the 7894 period, which can absorb sufficient energy from the sea as they moved a long distance over the sea, was stronger than that of 9512. Large-scale environments were analyzed to determine the cause of such difference in TC activity occurred between two periods. During the 9512 period, anomalous cold and dry anticyclones were developed strongly in the East Asia continent. As a result, Korea and Japan were affected by the anomalous northerlies thereby preventing TCs in this period from moving toward the mid-latitude region in East Asia. Instead, anomalous easterlies (anomalous trade wind) were developed in the tropical western Pacific so that a high passage frequency from the Philippine to the south China region along the anomalous steering flows was revealed. The characteristics of the anomalous cold and dry anticyclone developed in the East Asia continent were also confirmed by the analysis of air temperature, relative humidity and sensible heat net flux showing that most regions in East Asia had negative values.

• Journal of the Korean Electrochemical Society
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• v.10 no.3
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• pp.196-202
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• 2007

The performance characteristics of the polymer electrolyte fuel cells (PEFCS) were investigated under various humidification conditions at steady-state and transient conditions. The PEFC studied in this study was characterized by I-V curves in the potentiostatic mode and EIS (electrochemical impedance spectroscopy). The I-V curves representing steady-state performance were obtained from OCV to 0.25 V, and the dynamic performance responses were obtained at some voltages. The effects of anodic external humidification were measured by varying relative humidity of hydrogen from 20% to 100% while dry air was supplied in the cathode. At the high voltage region, the performance became higher with the increase of the temperature, while at the low voltage region, the performance decreased with the increase of temperature. The EIS showed that ohmic losses were larger at the dry condition of membrane and the effects of mass transport losses increased remarkably when the external and self-humidification were high. The dynamic responses were also monitored by changing the voltage of the PEFC instantly. As the temperature increased, the current reached steady-state earlier. The self-humidification with the generated water delayed the stabilization of the current except for low voltage conditions.

• Horticultural Science & Technology
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• v.32 no.4
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• pp.493-498
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• 2014

The objective of this study was to make growth and yield models for common ice plant (Mesembryanthemum crystallinum L.) using expolinear functional equations in a closed-type plant production system. Three-band radiation type fluorescent lamps with a 12-hours photoperiod were used, and the light intensity was $200{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. Nutrient film systems with three layers were used for plant growth. Environmental conditions, such as air temperature, relative humidity and $CO_2$ concentration were controlled by an ON/OFF operation. Leaf area, shoot fresh and dry weights, light use efficiency of common ice plant as function of days after transplanting, accumulative temperature and accumulative radiation were analyzed. Leaf area, shoot fresh and dry weights per area were described using an expolinear equation. A linear relationship between shoot dry and fresh weights was observed. Light use efficiency of common ice plant was $3.3g{\cdot}MJ^{-1}$ at 30 days after transplanting. It is concluded that the expolinear growth model can be a useful tool for quantifying the growth and yield of common ice plant in a closed plant production system.

• Korean Journal Plant Pathology
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• v.3 no.3
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• pp.210-216
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• 1987

A computer program written to predict blast occurrence based on micro climatic events was developed and tested as an on-site microcomputer in field plots in 1984 and 1985. A microcomputer unit operating on alkaline batteries; continuously monitored air temperature, leaf wetness, and relative humidity; interpreted the microclimate information in relation to rice blast development and displayed daily values (0-8) of blast units of severity (BUS). Cumulative daily BUS values (CBUS) were highly correlated with blast development on the two susceptible cultivars, M-201 and Brazos grown in field plots. When CBUS values were used to predict the logit of disease proportions, the average coefficients of determination $(R^2)$ between these two factors were 71 to $91\%$, depending on cultivar and year. This was a significant improvement when compared to 61 to $79\%$ when days were used as a predictor of logit disease severity. The ability of CBUS to predict logit disease severity was slightly less with Brazos than M-201. This is significant inasmuch as Brazos showed field resistance at mid-sea­son. The results in this study indicate that the model has the potential for future use and that the model could be improved by incorporating other variables associated with host plants and pathogen races in addition to the key environmental variables.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.1
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• pp.157-165
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• 2020

Objective: The objective of this study was to compare the quality of dry-aged beef from cull Hanwoo cows slaughtered at 60 or 80 months old. Methods: A total of eight cull Hanwoo carcasses with a quality grade of 3 (low-grade) were selected and divided into two age groups: 63.5±2.5 months old (n = 4) and 87.8±4.5 months old (n = 4). Whole longissimus thoracis et lumborum from the 11th rib to the last lumbar vertebrae, including the back fat, was removed from the carcass at 24 h postmortem and aged for 50 days in darkness at a temperature of 2℃±1℃, a relative humidity of 85% and an air flow of 2 m/s. The sampling was performed aseptically after 0, 20, 24, 40, and 50 days of aging. Results: Regardless of the aging period, aging increased the lightness (p<0.05), redness (p<0.05) and yellowness (p<0.05) at initial blooming (90 min after slicing) and the overall acceptance (p<0.05). No further tenderization effect was found after 20 days of aging, but aging for 50 days significantly increased the lipid oxidation (p<0.05). The generation of aroma volatiles in the roast steak from aged samples was higher (p<0.05) than that of non-aged samples. No significant effect of age at slaughter was found on the color, pH, water-holding capacity, cooking loss, shear force value, bacterial counts, volatile basic nitrogen, consumer acceptance, lipid oxidation, fatty acid composition or aroma volatiles. Conclusion: The quality of dry-aged beef obtained from cull Hanwoo cows slaughtered at either 60 or 80 months old with similar quality grade was comparable and extending dry aging for more than 40 days is not recommended considering the costs and further lipid oxidation.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.5
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• pp.105-112
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• 2017

In order to analyze the effect of street trees on human thermal sensation(thermal comfort) in summer, microclimatic data were measured and analyzed at sunny and shaded locations of two deciduous broadleaf and three broadleaf evergreen species of street trees. As a result, the mean differences by species in air temperature, relative humidity and wind speed were small: $0.2{\sim}1.5^{\circ}C$, 0.9~5.3% and $0.1{\sim}0.5 ms^{-1}$, respectively, but the mean difference in the mean radiant temperature was great, $27.1^{\circ}C$. In the results of physiological equivalent temperature(PET) and universal thermal climate index(UTCI), which are human thermal sensation(thermal comfort) indexes, the shaded locations by the trees showed mean reduction rates of 21.2~31.3% in the PET compared with the sunny location, which are equivalent to 1.5~2.5 levels of thermal perception. Also, 12.7~20.0% in the UTCI was reduced by the trees' shadows, which is equivalent to 1~1.5 levels of heat stress. In addition, although the broadleaf evergreen trees had 5% greater mean reduction in PET than that of the deciduous broadleaf trees, the Zelkova serrata that belonged to the deciduous broadleaf trees showed the equivalent thermal reduction effect as the broadleaf evergreen trees because of the high density of branches and leaves. Therefore, the mean radiant temperature and the density of the crown(branches and leaves) were the main influences in thermal modification by these street trees in summer.